Grinding-mill



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Grindi'ngMrill.

No. 235,422. Patented Dvec'. 14, 1880.

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N.FETERS, FHDTO-LITHUGRAPHER. WASHINGTON. D C.

4 'y l i Y h l-sheets-slhlee; 3. J. FITZGERALD.

Grinding Mill.

No. .235,4'22.' i Patented Dec. 14,1880.

UNITED A`Staken-s PATENT kuren.

JOHN FITZGERALD, OF BROOKLYN, NEW YORK.

GRlNDlN'G-MILL.

SPECIFICATION forming part of Letters Patent No. 235,422, dated December 14, 1880,

Application filed November 4, 1879.

To all whom t may concer/n:

Beit known that I, JOHN FITZGERALD, of Brooklyn, Kings county, New York, haveinvented certain Improvements in Grinding- Mills, of which the following is a specication, referencebein g had to the accompanying drawings, forming part of the same, in which- Figure lis a side elevation of a mill containing my improvements. Fig. 2 isa central vertical section of the same. Fig. 8 is a plan or top view of the hopper and dome, as shown in Fig. 2. Fig. 4 is a view looking down on a cross-section on line y y, Fig. 2. Fig. 5 is a horizontal section throughthe `lower stone of the mill, about midway betweenthe upper and under surface. Fig. 6 is a detailed view, in section, of my hopper and its dome, and showing the supplementary feeding-hopper and its valve, whereby the main hopper is fedfwith' material to be groundat the same time that the air in the said hopper is prevented from' escaping.

When grinding-mills are run at a-high speed the stones are liable to becomeob'jectionably` The object of my improvementis to` heated. effect their cooling by the circulation of air or water around and between them.

A represents the frame on which the working parts are mounted, consisting of upright posts a, tied together by cross-bars or girders a' a?. The upper stone, B, is suspended to an iron plate, O, to which it is firmly secured, the said plate resting upon and made fast to the upper ends of the posts c, the stone being thus made stationary. The lower stone, B rests on and is secured to a plate or casing, O', which is formed, as shown plainly in section in Fig. 2, to t at its center onto a spindle, D, the said spindle atb, near its upperend, being squared and tted into a rectangular flange that projects from the under side of thecenter of the said'casing C. The central openin gin the casing is round, iitting the portion 'd of the spindle, the said casi-ng with the lower stone thus resting on the-spindle D, by which it is rotated.

`E is a supplemental grinder and mixer, which may be made of iron, beinga disk that covers the central opening `in the lower stone, B,-and rests upon and is made fasttoit. Its upper face is conical, as shown, and is provided `out between the grinders.

`ity ofthe lower grinder, E, and the under in ner edge is beveled or rounded off', as shown, so that the substance or material to be ground will make its way through the center of E The grinder E is provided with a yoke, f, which rises from the `grinder, within the hopper F, that is connected with the top plate or casing, C. On two opposite sides of the inner wall of this hopper are ribs forming ways, in which lugs or projectionsf f2 on the yoke work. This arrangement, while it permits the grinder E to have a vertical movement, prevents it from revolving.

lt is also evident that by this arrangement the upper auxiliary grinder, E', is detached from and unconnected with the upper stone, B, so that it is possible for a space or chamber to exist between the adjacent faces of the grinder E and stone B, and these parts are so constructed and arranged that the space x shall exist between the outer edge of E and the interior edge of B, so that communication yis established bptween the grinding-surfaces of B and B and the interior of the hopper F, above the Lipper auxiliary grinder, E. By this means the material to be ground, passing down between the auxiliarygrinders E E to the stones B B', if itis notcrushed fine enough to enter between said stones, will be crowded up into the space x, and thence will pass up over the ring-grinder E into the hopper, and will then pass again through the auxiliary grinders E E to be recrushed.

Upon the outer rim ot the ring-grinder E', I place one or more wings, which project from the face of E and extend downward along said face in the space between said face and the adjacent surface ot' B. These wings are preferably formed of strips ot' an gle-iron, as shown `at y', Fig. 2, where one is seen bolted onto the outer rim of E in the space These ICO wings are so attached to the ring-grinder li that they may be inclined more or lesson the face of E to dip to a greater or less degree downward toward the bottom ot' the space or chamber .r. 'lhese wings or inclined projections y thus operate, when E is rotating, as scoops or inclines to force or carry the imiterial which tinds its way into the chamber .1', in which they travel, upward and over E into the hopper again. This prevents any clogging in the space .1, and any coarse particles ot' the material being ground are readily carried up out of said space or chamber and returned with the general lnass to the grinders li E.

The tendency ot' the screw-stirrer J is to gather the material in the hopper toward the center and to crowd it down through the eentral opening ot' E to and between the grinders EE', while the wings or inclines y on the outer face of E', lnoving in the chamber .1', will operate to force upward and into the hopper all particles ot' the material which are not tine enough to enter between the stones l; i.

G is a beveled gear, which is hung on brackets g g', which take into an annular groove in the hub of said gear, as shown in Fig. The said gear is driven by a pinion, (if, on the driving-shatt (if. The spindle l) passes loosely through the hub ot' (i, to which it is feathered, and is stepped on a sliding bloek or step, 1)', the said block restingon a lever, 1)?, which is pivoted at one end, at l1, to the crossbar a2, tite opposite end being connected to a screw-rod, h', that passes through a brael-iet, with a nut hamLwheel, 1F. whereby the block D', the spindle l), and consequently the stone B and grinder E, may be raised and lowered to adjust the stones for grinding.

From the center of the cap or cover F'z of the hopper F rises a dome or cylinder, It', closed at the top and provided with a weighted valve, 'L'.

j and j are rods` which run through stutlingboxes down through the cap F2, and rest at their lower ends on the projections f f on the yokef. 0n the upper ends ot' these rods are weights jl j, which serve to press the grinder E upon E.

I will now proceed to describe the devices by which air or water is circulated over and around the stones, whereby they are cooled.

Between the upper and lower surfaces, respectively, ot' the stones and the casings C and C' heretofore mentioned there are spaces or chambers o o', as shown in Fig. 2. In these chambers are placed series ot radial partitions p, arranged to abut alternately against the outer and inner walls ot' the chambers, as seen in dotted linesin Figs. 4 and 5. Thereby air or iuid circulating around these chambers will be made to take a zigzag course around the open ends of the partitions. Air or tiuid is introduced into these chambers through the pipe H, which branches, one branch, H', leading into the chamber o over the stone 15. and the other branch, 112, through an annular chamber, m, in the cylinder I, which is secured on the lower bar, n', and projects upward into the center ot' the casing C. From this annular chamber the air passes through an opening, n, in the said casing down into the cham ber o; thence, at'ter passing around the said chambers past the partitions, passes out through a channel, yn', into a pipe, n2, which runs through the center of the grinder E, and rises and opens into the dome k. The course ot" the air is indicated by arrows in Fig. 2. The air entering through branch pipe H' passes around the stone B, through the chamber o, past the radial partitions in that chamber, and escapes through the pipe H3 into the dome 1.'. The authus coming into the dome through the pipes In and H3 is forced downward upon and into the contents of the hopper F, and makes its way, mingled with said contents, between the grinders E and E and the stones B and B. The stones and grinders are thus surrounded by a moving current of cold air, whereby they are kept cool.

The casings ot the stones may be lnade to include in the chambers o o a space around their peripheries, thus enlarging the surface with which the cold air is brought in contact.

J is a screw-stirrer tixed ou the pipe n, by the revolving ot' which the contents ot' the hopper F are forced down into the mill, aided by the air-pressure above. The motion of the stirrer also gives access to the air into the said coiltents.

'lhe casing C, with the stone B, is vertically adjustable on the traine A by means of setscrews, and is held down onto said frame by means of screw-bolts t and nuts t and t2, which may be pivoted or hinged at their lower ends to the trame and swing into slots in the casing.

1t, Fig. 6, represents a mouth-piece for the introduction ot' the material to be ground into the hopper F. It is provided with valve q at the bottom, that opens downward, and 1s kept closed by the stress of a spring, 15", which is so adjusted that it will give way to the pressure ofthe material iu the mouth-piece and close the valve when the mouth is empty.

K is a valve in the form of a disk, which is titted loosely upon the pipe n2, and rests on the top of the yoke f when not lifted therefrom. It is constructed, when raised, to close the lower end of the dome or cylinder k, the design being that it shall be oated on the top of the contents of the hopper and close the said dome, so that said contents cannot rise into the dome and make their way into the air-pipes.

It is intended that a suitable air-pump or blower shall be employed to force the air into the chambers o o through the pipes H H2.

I am aware that chambers have heretofore been formed between the stones ot' a mill and their casings provided with radial partitions, whereby air for cooling the stones is made to pass through these chambers over the surface IIO of the stones in a zigzag course, and hence I do not claim this as new. I intend to limit my claims hereunder to the specific devices shown and described whereby the circulation of the air through and around the stones is accomplished.

I am also aware that heretofore mills have been constructed with devices by which a blast of air has been caused to mingle with the material to be ground as it passes between the grinders; hence I do not intend to claim this, broadly; but I wish to limit my claims hereunder to the devices whereby at the same time the air is forced into the hopper of the mill under pressure and is there mingled with the material as itpasses to the grinders. The air cannot escape from'the hopper in any other direction, although the material to be ground can be fed into the hopper as desired.

What I claim as myiuvention, and desire to secure by Letters Patent, is-

l. The combination, with the stones B B', of the casings C G', chambers 0 and o', the pipes H H2, the air-passagesa a', the annular chamber' m in the cylinder I, and the pipes H3 and a2, all constructed to operate as and for the purpose described.

2. The combination of the rotating stone B', the casing C', chamber o', and cylinder I, ttin g into and forming a joint With said casing, as shown in Fig. 2of the drawings, and provided with the annular chamber m, as and for the purpose specified.

3. The combination, with the stones B B', of the hermetically-closed hopper F, provided with the spring-valve q in the auxiliary feeding hopper or funnel R, and pipes H3 and n2 for conducting air under pressure into said hopper F, as described, whereby an air-pressure is applied to the contents ofthe hopper to force the same, mingled with the air, between the stones, and at the same time the hopper F may be fed or supplied with the material to be ground without the escape of the air under pressure in the hopper, as and for the purpose specified.

4. The combination, with the stones B B', of the auxiliary grinders E E', as described, the grinder E' having the chamber between its outer face and the interior face of B, and having the adjustable inclined wings or pieces y' on its outer rim, as described, together with the screw J, all arranged to operate as and for the purpose specified.

5. The combination, with the grinders and mixers E E', of the yokef, having lugs f'f" engaging in ways on the interior of the hopper F, the rods jj', and weights jzjs, as and for the purpose specified.

6. The combination, with the stones B B', of the hopper F and dome 7c and air-pipes H3 and u2, together with the valve K, as described, and for the purpose specified.

7. The combination, with the hopper F and dome 7c, ofthe valve K, fitted to slide on the pipe u2, as and for the purpose described.

JOHN FITZGERALD.

WVitnesses:

JOHN G. H. MEYERs, M. F. CLIFTON. 

